    $white: #fff !default;
    $gray-100: #f8f9fa !default;
    $gray-200: #e9ecef !default;
    $gray-300: #dee2e6 !default;
    $gray-400: #ced4da !default;
    $gray-500: #adb5bd !default;
    $gray-600: #6c757d !default;
    $gray-700: #495057 !default;
    $gray-800: #343a40 !default;
    $gray-900: #212529 !default;
    $black: #000 !default;

    $blue: #0d6efd !default;
    $indigo: #6610f2 !default;
    $purple: #6f42c1 !default;
    $pink: #d63384 !default;
    $red: #dc3545 !default;
    $orange: #fd7e14 !default;
    $yellow: #fadb14 !default;
    $green: #52c41a !default;
    $teal: #20c997 !default;
    $cyan: #17a2b8 !default;

    $primary: $blue !default;
    $secondary: $gray-600 !default;
    $success: $green !default;
    $info: $cyan !default;
    $warning: $yellow !default;
    $danger: $red !default;
    $light: $gray-100 !default;
    $dark: $gray-800 !default;

    $theme-colors: (
      "primary": $primary,
      "secondary": $secondary,
      "success": $success,
      "info": $info,
      "warning": $warning,
      "danger": $danger,
      "light": $light,
      "dark": $dark
    );

    $font-family-sans-serif: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol", "Noto Color Emoji" !default;
    $font-family-monospace: SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace !default;
    $font-family-base: $font-family-sans-serif !default;

    // 字体大小
    $font-size-base: 1rem !default; // Assumes the browser default, typically `16px`
    $font-size-lg: $font-size-base * 1.25 !default;
    $font-size-sm: $font-size-base * .875 !default;
    $font-size-root: null !default;

    // 字重
    $font-weight-lighter: lighter !default;
    $font-weight-light: 300 !default;
    $font-weight-normal: 400 !default;
    $font-weight-bold: 700 !default;
    $font-weight-bolder: bolder !default;
    $font-weight-base: $font-weight-normal !default;

    // 行高
    $line-height-base: 1.5 !default;
    $line-height-lg: 2 !default;
    $line-height-sm: 1.25 !default;

    // 标题大小
    $h1-font-size: $font-size-base * 2.5 !default;
    $h2-font-size: $font-size-base * 2 !default;
    $h3-font-size: $font-size-base * 1.75 !default;
    $h4-font-size: $font-size-base * 1.5 !default;
    $h5-font-size: $font-size-base * 1.25 !default;
    $h6-font-size: $font-size-base !default;

    // 链接
    $link-color: $primary !default;
    $link-decoration: none !default;
    $link-hover-color: darken($link-color, 15%) !default;
    $link-hover-decoration: underline !default;

    // body
    $body-bg: $white !default;
    $body-color: $gray-900 !default;
    $body-text-align: null !default;

    // Spacing
    $spacer: 1rem !default;

    // Paragraphs

    $paragraph-margin-bottom: 1rem !default;

    // 字体其他部分 heading list hr 等等
    $headings-margin-bottom: $spacer / 2 !default;
    $headings-font-family: null !default;
    $headings-font-style: null !default;
    $headings-font-weight: 500 !default;
    $headings-line-height: 1.2 !default;
    $headings-color: null !default;

    $display1-size: 6rem !default;
    $display2-size: 5.5rem !default;
    $display3-size: 4.5rem !default;
    $display4-size: 3.5rem !default;

    $display1-weight: 300 !default;
    $display2-weight: 300 !default;
    $display3-weight: 300 !default;
    $display4-weight: 300 !default;
    $display-line-height: $headings-line-height !default;

    $lead-font-size: $font-size-base * 1.25 !default;
    $lead-font-weight: 300 !default;

    $small-font-size: .875em !default;

    $sub-sup-font-size: .75em !default;

    $text-muted: $gray-600 !default;

    $initialism-font-size: $small-font-size !default;

    $blockquote-small-color: $gray-600 !default;
    $blockquote-small-font-size: $small-font-size !default;
    $blockquote-font-size: $font-size-base * 1.25 !default;

    $hr-color: inherit !default;
    $hr-height: 1px !default;
    $hr-opacity: .25 !default;

    $legend-margin-bottom: .5rem !default;
    $legend-font-size: 1.5rem !default;
    $legend-font-weight: null !default;

    $mark-padding: .2em !default;

    $dt-font-weight: $font-weight-bold !default;

    $nested-kbd-font-weight: $font-weight-bold !default;

    $list-inline-padding: .5rem !default;

    $mark-bg: #fcf8e3 !default;

    $hr-margin-y: $spacer !default;

    // Code

    $code-font-size: $small-font-size !default;
    $code-color: $pink !default;
    $pre-color: null !default;

    // options 可配置选项
    $enable-pointer-cursor-for-buttons: true !default;

    // 边框 和 border radius

    $border-width: 1px !default;
    $border-color: $gray-300 !default;

    $border-radius: .25rem !default;
    $border-radius-lg: .3rem !default;
    $border-radius-sm: .2rem !default;

    // 不同类型的 box shadow
    $box-shadow-sm: 0 .125rem .25rem rgba($black, .075) !default;
    $box-shadow: 0 .5rem 1rem rgba($black, .15) !default;
    $box-shadow-lg: 0 1rem 3rem rgba($black, .175) !default;
    $box-shadow-inset: inset 0 1px 2px rgba($black, .075) !default;

    // 按钮
    // 按钮基本属性
    $btn-font-weight: 400;
    $btn-padding-y: .375rem !default;
    $btn-padding-x: .75rem !default;
    $btn-font-family: $font-family-base !default;
    $btn-font-size: $font-size-base !default;
    $btn-line-height: $line-height-base !default;

    //不同大小按钮的 padding 和 font size
    $btn-padding-y-sm: .25rem !default;
    $btn-padding-x-sm: .5rem !default;
    $btn-font-size-sm: $font-size-sm !default;

    $btn-padding-y-lg: .5rem !default;
    $btn-padding-x-lg: 1rem !default;
    $btn-font-size-lg: $font-size-lg !default;

    // 按钮边框
    $btn-border-width: $border-width !default;

    // 按钮其他
    $btn-box-shadow: inset 0 1px 0 rgba($white, .15), 0 1px 1px rgba($black, .075) !default;
    $btn-disabled-opacity: .65 !default;

    // 链接按钮
    $btn-link-color: $link-color !default;
    $btn-link-hover-color: $link-hover-color !default;
    $btn-link-disabled-color: $gray-600 !default;


    // 按钮 radius
    $btn-border-radius: $border-radius !default;
    $btn-border-radius-lg: $border-radius-lg !default;
    $btn-border-radius-sm: $border-radius-sm !default;

    $btn-transition: color .15s ease-in-out, background-color .15s ease-in-out, border-color .15s ease-in-out, box-shadow .15s ease-in-out !default;

    // alert
    // 基本属性                 
    $alert-padding-y: .75rem !default;
    $alert-padding-x: 1.25rem !default;
    $alert-font-size: $font-size-base !default;
    $alert-border-width: $border-width !default;
    $alert-border-radius: $border-radius !default;

    // 标题
    $alert-title-font-weight: 600 !default;

    // 描述
    $alert-description-font-size: $font-size-sm !default;

    // close图标
    $alert-close-top: .4rem !default;
    $alert-close-right: .7rem !default;
    $alert-close-font-weight: $alert-title-font-weight !default;
    $alert-close-font-size: $font-size-base !default;

    // menu
    $menu-border-width: $border-width !default;
    $menu-border-color: $border-color !default;
    $menu-box-shadow: inset 0 1px 0 rgba($white, .15), 0 1px 1px rgba($black, .075) !default;
    $menu-transition: color .15s ease-in-out, border-color .15s ease-in-out !default;

    // menu-item
    $menu-item-padding-y: .5rem !default;
    $menu-item-padding-x: 1rem !default;
    $menu-item-active-color: $primary !default;
    $menu-item-active-border-width: 2px !default;
    $menu-item-disabled-color: $gray-600 !default;

    //sub-menu
    //submenu
    $submenu-box-shadow: 0 2px 4px 0 rgba(0, 0, 0, .12), 0 0 6px 0 rgba(0, 0, 0, .04);

    // tabs
    $tabs-border-width: $border-width !default;
    $tabs-border-color: $border-width !default;
    $tabs-box-shadow: inset 0 1px 0 rgba($white, .15), 0 1px 1px rgba($black, .075) !default;

    // tabs-item
    $tabs-item-padding-y: .5rem !default;
    $tabs-item-padding-x: 1rem !default;
    $tabs-item-active-color: $primary !default;
    $tabs-item-active-border-width: 2px !default;
    $tabs-item-disabled-color: $gray-600 !default;

    // tabs-content
    $tabs-content-padding-y: .5rem !default;
    $tabs-content-padding-x: 1rem !default;

    //input
    $input-padding-y: .3rem !default;
    $input-padding-x: .6rem !default;
    $input-font-family: $btn-font-family !default;
    $input-font-size: $btn-font-size !default;
    $input-font-weight: $font-weight-base !default;
    $input-line-height: $btn-line-height !default;

    $input-padding-y-sm: .2rem !default;
    $input-padding-x-sm: .5rem !default;
    $input-font-size-sm: $btn-font-size-sm !default;

    $input-padding-y-lg: .4rem !default;
    $input-padding-x-lg: .7rem !default;
    $input-font-size-lg: $btn-font-size-lg !default;

    $input-bg: $white !default;
    $input-disabled-bg: $gray-200 !default;
    $input-disabled-border-color: null !default;

    $input-color: $gray-700 !default;
    $input-border-color: $gray-400 !default;
    $input-border-width: $border-width !default;
    $input-box-shadow: $box-shadow-inset !default;

    $input-border-radius: $border-radius !default;
    $input-border-radius-lg: $border-radius-lg !default;
    $input-border-radius-sm: $border-radius-sm !default;

    $input-focus-bg: $input-bg !default;
    $input-focus-border-color: lighten($primary, 15%) !default;
    $input-focus-width: .125rem !default;
    $input-focus-color: $input-color !default;
    $input-focus-shadow-color: rgba(5, 145, 255, 0.1) !default;
    $input-focus-shadow-error-color: rgba($danger, .25) !default;
    $input-focus-box-shadow: 0 0 0 $input-focus-width $input-focus-shadow-color !default;
    $input-focus-box-shadow-error: 0 0 0 $input-focus-width $input-focus-shadow-error-color !default;

    $input-placeholder-color: $gray-600 !default;
    $input-plaintext-color: $body-color !default;

    $input-height-border: $input-border-width * 2 !default;

    $input-transition: border-color .2s ease-in-out, box-shadow .2s ease-in-out !default;

    $input-icon-padding-x: 1.5rem !default;
    $input-icon-translate-x: translateX(.2rem) !default;
    $input-icon-font-size: $btn-font-size !default;

    $input-prefix-suffix-color: $input-color !default;
    $input-prefix-suffix-bg: $gray-200 !default;

    // AutoComplete
    $auto-max-height: 200px !default;
    $auto-padding: .5rem .2rem !default;
    $auto-box-shadow: $box-shadow !default;
    $auto-item-border-radius: $border-radius !default;
    $auto-item-padding: .3rem .7rem !default;
    $auto-item-transition: background-color .3s ease-in-out !default;

    // Progress bars

    $progress-font-size: $font-size-base * .75 !default;
    $progress-bg: $gray-200 !default;
    $progress-border-radius: $border-radius !default;
    $progress-bar-color: $white !default;
    $progress-bar-transition: width .6s ease !default;

    // Alerts
    //
    // Define alert colors, border radius, and padding.

    $alert-padding-y: .75rem !default;
    $alert-padding-x: 1.25rem !default;
    $alert-margin-bottom: 1rem !default;
    $alert-border-radius: $border-radius !default;
    $alert-title-font-weight: $font-weight-bold !default;
    $alert-border-width: $border-width !default;
    $alert-description-font-size: $font-size-sm !default;
    $alert-description-top-margin: .3rem !default;

    // Navs

    $nav-link-padding-y: .5rem !default;
    $nav-link-padding-x: 1rem !default;
    $nav-link-disabled-color: $gray-600 !default;

    $nav-tabs-border-color: $gray-300 !default;
    $nav-tabs-border-width: $border-width !default;
    $nav-tabs-border-radius: $border-radius !default;
    $nav-tabs-link-hover-border-color: $gray-200 $gray-200 $nav-tabs-border-color !default;
    $nav-tabs-link-hover-color: $primary !default;
    $nav-tabs-link-active-color: $primary !default;
    $nav-tabs-link-active-bg: $body-bg !default;
    $nav-tabs-link-active-border-color: $gray-300 $gray-300 $nav-tabs-link-active-bg !default;
    $nav-tabs-content-margin: 1rem !default;